Rolling machine



E. C. HANNA ROLLING MACHINE Dec. 3, 1963 2 Sheets-Sheet 1 Filed April 7, 1959 INVENTOR EDWARD C. HANNA M%M ATTORNEYS E. C. HANNA ROLLING MACHINE Dec. 3, 1963 Filed April 7, 1959 2 Sheets-Sheet 2 INVENTOR EDWARD C. HANNA ATTORNEYS United States Patent 3,112,662 RGLLENG MACHINE Edward C. Hanna, Wayneshero, Pa, assignor to Landis Machine Company, Waynesboro, Pa. Filed Apr. 7, 1959, Ser. No. it- 3,664 5 Claims. (Cl. 80-56) This invention relates to machines for roll-forming work pieces, especially machines for rolling profiles such as screw threads upon the surfaces of cylindrical blanks. In particular the invention concerns machines having a pair of rotatively driven cylindrical dies, one mounted upon a stationary axis, the other upon a laterally movable axis.

Heretofore such machines have been constructed so as to absorb the stresses incident to rolling through the bed of the machine. Several disadvantages are inherent in that mode of construction. First, the members under stress are large and, since deflection is proportional to size, either the entire machine is too resilient to form the work pieces accurately or the bed of the machine has to be made extremely heavy or has to be reinforced with tie rods or the like. In addition to deflection due to the rolling forces, thermal deflection also decreased the ac curacy of the machine. As a machine warmed up under operation the stressed members, i.e., portions of the bed, long tie rods, etc., expanded increasingly and this thermal deflection was reflected in the accuracy of the product.

The machines of the present invention minimize the length of the members stressed by the rolling operation and reduce the portion of the rolling forces passing through the bed of the machine to a minimum. This is done by connecting both rolling dies directly to a short linkage or toggle mechanism which absorbs the principal rolling stresses. Thus the above-mentioned disadvantages are simultaneously obviated. A further advantage resides in the fact that the machine bed can now be made without tie rods and without unduly massive construction without decreasing the tool rigidity.

It is widely recognized as an advantage in thread rolling machines of this general type that the movable rolling die be caused to decrease its rate of penetration in the radial direction as the operation proceeds. Thus the rate of penetration becomes inversely proportional to the rate of volumetric displacement of material and when a large volume of material is being moved, as near the end of an operation, the penetration rate is low. This effect has heretofore been possible by the use of special and expensive cam means for operating the movable die. In the machine of this invention this result is achieved by the utilization of the toggle system mentioned above and supplementary cam means is unnecessary.

Extremely high rolling pressures can be obtained with the device of the invention with a very low force input. In one position of the toggle mechanism the rolling force approaches infinity yet the mechanism can be operated with one low-powered fluid cylinder.

Accordingly it is an object of the invention to provide a novel thread or profile rolling machine operating upon a new principle and having one stationary-axis die and one movable-axis die, in which the principal rolling stresses are contained within the mechanism for operating the movable die and are not transmitted through the bed of the machine.

Another object is to provide a thread rolling machine as described above in which the movable-axis die is mounted on a rocking member which in turn is pivotally mounted on the bed.

A further object of the invention is to provide a thread rolling machine of the type described in which both rolling dies are connected, each by means of a pair of links to an operating cylinder.

It is a still further object to provide a rolling machine in which the deflections due to mechanical stresses and those due to temperature variations are both minimized.

Another object is to provide a machine in which the system of links mentioned produces a decelerating rate of penetration by the rolling dies so that the penetration rate is substantially inversely proportional to the volumetric rate of displacement of material of the work piece.

It is also an object to provide a system of links for operating a rolling machine which is so arranged that the effects of thermal expansion on one portion of the link system is substantially concelled by thermal expansion of another portion of the link system.

Further objects and advantages will be apparent from the following escription of an exemplary embodiment of the invention and from the accompanying drawings, in which:

FIGURE 1 is a front elevation of the machine with a portion of the forward wall broken away;

FIGURE 2 is a transverse sectional view, partly along line 22 of FIGURE 3; and

FIGURE 3 is a substantially horizontal sectional view taken along line 3-3 of FIGURE 2.

The machine comprises a sub-base 20 which may be employed to house a coolant tank and other incidental apparatus. The bed 22 is mounted upon sub-base 2i and is provided with platforms 24 and 26 (FIGURE 2) to receive a swivel housing 23. The swivel housing 28 is pivotally mounted on the bed 22 by means of a vertically disposed pivot pin 39 passed therethrough and through the platform 26. The pivot pin 30 is held axially between a shoulder 32 above the platform and a Washer 34 and screw 36 below the platform. Near the outer end of swivel housing 28 a screw 38 supported by a washer 40 is passed through an enlarged opening in the housing and engages the platform 24. Thus the swivel housing 28 has a limited amount of angular adjustment in the horizontal plane and is held in adjusted position by the screw 33.

The swivel housing 28 is provided with a large transverse bore 42 in which is disposed a cylindrical member 44. A cap 46 closes the outer end of the bore 42 and is attached to the cylindrical member 44 by means of a central screw 48. The screw 48 is prevented from turning relative to the cap 46 by means of a plurality of screws 59 which pass through the head of the screw 48 and engage the cap 46. The inner portion of the cylindrical member 44 is provided with screw threads on its circumference which are engaged by a nut 52. The nut 52 is kept in close engagement with a surface of the swivel housing 28. The cylindrical member 44 is thus rendered axially adjustable toward and away from its limit position as shown by rotating the cap 46 and screw 48 and the nut 52.

An inwardly projecting integral pivot pin 54 is provided on the inner end of cylindrical member 44. A plate 56 is mounted on the pin 54 and is secured by screws (not shown) to the cylindrical member 44. A rectangular bar 58 is attached to the bottom surface of plate 5:; to prevent the plate from being rotated out of position. A spindle housing 60 is also rockably mounted on the pin 54 and rotatably supports a spindle 62 upon which a rolling die 64 is journalled, the die being constrained to rotate therewith by means of a key 66. The details of the mounting of the spindle housing 66 and die 64 are completely conventional and may be such as to permit the spindle housing 60 to be rotated about the axis of pin 54 relative to the plate 56 to incline the axis of the rolling die 64 in a vertical plane and relative to the axis of a work piece.

A shaft 63 is mounted near the bottom of the bed 22 (FIGURE 1) to serve as the fulcrum for a large rockable bracket 7%. Near its top the bracket 79 is formed to receive a cylindrical stud 72 which is secured to the bracket 79 by a screw 74. Surrounding the stud 72 is a plate 76 corresponding to and facing the plate 56. The plate 76 is secured by screws (not shown) to a surface of the bracket 70 and is prevented from rotating about the stud 72 as a pivot by means of a shoulder 7 8 on the bracket. The stud 72 also serves as a pivot pin for a second spindle housing 80, rockably mounted thereon. The spindle housing 80 rotatably supports a spindle 82 which has a rolling die 84 journalled thereon. The die 84 is constrained to rotate with spindle 82 by means of a key 86 and is mounted in opposed relationship to the rolling die 64. As in the case of the die 64, the die 84 is conventionally mounted and driven and the housing 80 may also be rotated relative to the plate 76 so as to incline the axis of the rolling die 84 in a vertical plane and relative to the axis of the work piece as is well understood in the art. The spindles 62 and 82 are driven at the same speed and in the same direction by conventional drive mechanism, not shown.

At its inner end the swivel housing 28 is provided with a large, rectangular, horizontal slot 88 which is occupied by a swivel member 90. The swivel 90 is retained in the slot 88 by the pivot pin 3%) which passes vertically through the slot. At each side of the swivel 99 a pin 92 is formed integrally therewith (FIGURE 3). A pair of long links 94, 96 are journalled upon the pins 92 and are secured thereon by means of screws 98 and washers 1%. The links 94 and 96 extend outwardly toward the side of the machine and at their outer ends are joined by a shaft 102. Screws 194 and washers 196 are employed to secure the links 94 and 96 upon the ends of shaft 102.

Between the links 94 and 96 the shaft 162 is surrounded by a bearing bushing 108 upon which is journalled a short link 110. The link 110- extends inwardly toward the center of the machine and at its inner end is journalled upon a bushing 112 which surrounds a shaft 114 mounted in bush ings 116 in the rocker bracket 7 0. The shaft 114 and bushings 112 and 116 are maintained in axial position by the long links 94 and 96 which lie closely adjacent the ends of the shaft 114 and the side surfaces of bracket 70. At its outer end the link 110 is bifurcated to admit a clevis bolt 118 (FIGURES 2 and 3) which is also journalled upon bushing 108 on shaft 102. The clevis bolt 118 is threadedly engaged in the piston rod 120 of a pneumatic cylinder 122. The head end of cylinder 122 is pivot-ally'mounted upon a pin 124 supported in the bed 22.

Before beginning operation of the machine the stationary-axis die 64 is first adjusted to the desired position by suitably rotating the cap 46 and nut 52 thus disposing the periphery of die 64 at the required distance from the opposed periphery of die 84. The drive to spindles 62 and 82 is then set in motion, rotating the dies 64 and 34 at the same speed and in the same direction and a work piece blank is introduced between the dies. Air is then admitted, by either manual or automatic control means, to the head end of the cylinder 122, forcing the piston rod 129 upwardly. In this movement the shaft 102 is constrained to rotate bodily about the centers of the pins 92 since the latter are held stationary by the swivel 9t and pivot p Thus as the links 94 and 26 move from the dotted-line position shown'in FIGURE 1 toward the full-line position, the outer end of the short link 116 is also carried upwardly upon the shaft 162. This causes the center of the shaft 114 to be forced inwardly toward the swivel 90 and causes the bracket 70 to be rocked in the counterclockwise direction. Consequently the die 84 carried by the bracket 7 is forced toward the die 64 and the profile formed on the dies is rolled upon the work piece.

It will be evident that the above-described mechanism and operation attains all the benefits listed above. For example, as the links 94 and 96 approach the full-line position of FIGURE 1, the lateral motion of the shaft 114 decreases proportionately. That is, as the rolling operation nears completion, the rate of penetration decreases. It will also be noted that the major portion of the rolling forces is contained in the assembly of links 94, 96 and 115 shafts 102 and 114 and swivel while only a negligible portion of the rolling force passes through the bed 22. Since the links 94, 9'6 and are relatively short, the elongation of the former and the shortening of the latter are low because of the fact that for a given applied stress, strain is proportional to length.

The effects of thermal expansion or contraction of the links 94, 96 is largely offset by the expansion or contraction of the link 110 and the net change of length of the system is caused only by expansion or contraction of that portion of the links 94, 96 which project beyond the link 11%.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come withinthe meaning and range of equivalency of the claims are therefore intended to be embraced therein. a

What is claimed and desired to be secured by United States Letters Patent is:

1. Apparatus for rollin workpieces comprising a main frame, a first roll, support means mounted on said main frame and supporting said roll for rotation about a relatively fixed axis, a second roll, a carrier rotatably supporting said second roll for rotation about an axis parallel to said fixed axis, means supporting said carrier on said frame for movement toward and away from said first roll, a first link pivotally connected at one end to said support means for said first roll and having a portion extending beyond said second roll, a motoroperatively connected to the projecting portion of said first link to swing said first link about its pivotal axis, and an additional link connected at its opposite ends, respectively, to said carrier and to the projecting portion of said first link to thereby move said carrier and said second roll toward and away from said first roll upon operation of said motor, the principal rolling loads being absorbed by said first link acting in tension and by said additional link acting in compression.

2. Apparatus for rolling workpieces comprising a main frame, a first roll, a swivel housing, a pivot pin mounting said swivel housing on said main frame for pivotal movement about a substantially vertical axis, means supporting said first roll on said swivel housing for rotation about a substantially horizontal axis, a rocker arm pivotally carried by said main frame, a second roll rotatably carried by said rocker arm for rotation about a substantially horizontal axis, a first link, a swivel member carried by said pivot pin, means pivotally connecting one end of said link to said swivel member, an additional link connecting the opposite end of said first link to said rocker arm, and motor means for swingin said links about their pivotal axes to thereby move said rocker arm and said second roll toward and away from said first roll.

3. The apparatus according to claim 2 wherein said swivel member is mounted with a close sliding fit in a horizontally extending slot formed in said swivel housing.

4. Apparatus for rolling workpieces comprising a main frame, a first roll, support means mounting said first roll adjacent the upper edge of said main frame for rotation about a relatively fixed axis, a rocker arm, means pivotally mounting the lower end of said rocker arm adjacent the lower edge of the main frame, said rocker arm projecting upwardly above said main frame, a second roll rotatably carried by said rocker arm adjacent its projecting upper end, a first link operatively connected at one end to said support means mounting said first roll, said first link having a portion projecting beyond said second roll, an additional link connecting the projecting portion of said first link to said rocker arm, and means for swinging said first link about its pivotal axis to move said rocker arm and thereby move said second roll toward and away from said first roll, the principal rolling loads being absorbed by said first link actin in tension and by said second link acting in compression.

5. Apparatus for rolling workpieces comprising a main frame, a first roll, support means mounting said first roll adjacent the upper edge of said main frame for rotation about a relatively fixed axis, a rocker arm, means pivotally mounting one end of said rocker arm adjacent the lower edge of said main frame, said rocker arm projecting upwardly above said main frame, a second roll rotatably carried by said rocker arm adjacent its upper projecting end, a first link operatively connected at one end to said support means for said first roll and having a portion extending beyond said second roll, a fluid motor operatively connected to the projecting portion of said first link to swing said first link about its pivotal axis, and an additional link connected at its opposite ends, respectively, to said rocker arm and the projecting portion of the said first link to thereby move said rocker arm and move said second roll toward and away from said first roll upon operation of said motor, the principal rolling loads being absorbed by said first link acting in tension and by said second link acting in compression.

References Qiterl in the file of this patent UNITED STATES PATENTS 2,182,906 Unke Dec. 12, 1939 2,548,444 Parker Apr. 10, 1951 2,590,667 Wittman Mar. 25, 1952 2,624,218 Flanders I an. 6, 1953 2,771,799 Batchelder Nov. 27, 1956 FOREIGN PATENTS 112,733 Great Britain July 12, 1917 537,768 Great Britain July 4, 1941 889,376 France Oct. 4, 1943 OTHER REFERENCES Toggle Linkage Applications in Different Mechanisms, Thomas P. Goodman, Product Engineering, Annual Handbook of Product Design of 1953, November 1952, pages F26, F27. 

1. APPARATUS FOR ROLLING WORKPIECES COMPRISING A MAIN FRAME, A FIRST ROLL, SUPPORT MEANS MOUNTED ON SAID MAIN FRAME AND SUPPORTING SAID ROLL FOR ROTATION ABOUT A RELATIVELY FIXED AXIS, A SECOND ROLL, A CARRIER ROTATABLY SUPPORTING SAID SECOND ROLL FOR ROTATION ABOUT AN AXIS PARALLEL TO SAID FIXED AXIS, MEANS SUPPORTING SAID CARRIER ON SAID FRAME FOR MOVEMENT TOWARD AND AWAY FROM SAID FIRST ROLL, A FIRST LINK PIVOTALLY CONNECTED AT ONE END TO SAID SUPPORT MEANS FOR SAID FIRST ROLL AND HAVING A PORTION EXTENDING BEYOND SAID SECOND ROLL, A MOTOR OPERATIVELY CONNECTED TO THE PROJECTING PORTION OF SAID FIRST LINK TO SWING SAID FIRST LINK ABOUT ITS PIVOTAL AXIS, AND AN ADDITIONAL LINK CONNECTED AT ITS OPPOSITE ENDS, RESPECTIVELY, TO SAID CARRIER AND TO THE PROJECTING PORTION OF SAID FIRST LINK TO THEREBY MOVE SAID CARRIER AND SAID SECOND ROLL TOWARD AND AWAY FROM SAID FIRST ROLL UPON OPERATION OF SAID MOTOR, THE PRINCIPAL ROLLING LOADS BEING ABSORBED BY SAID FIRST LINK ACTING IN TENSION AND BY SAID ADDITIONAL LINK ACTING IN COMPRESSION. 